Sitting down to a steaming bowl of paella–rice, broth, chorizo, clams and mussels–with a pitcher of Sangria is a fiesta for the tastebuds. It’s also a gastronomic adventure that can lead to serious illness caused by allergies, bacteria or Hepatitis A.

If you have a food allergy and are planning a trip abroad, you may have checked out our previous post.  But if you think you’re allergy-free, think again. Did you know that allergies often develop for the first time during your adult years? In fact, a shellfish allergy is the most common type to develop at a later age. According to the National Institute of Allergy and Infectious Diseases, seafood allergies affect only 0.6 percent of children but 2.8 percent of adults. So if it’s been a while since you sat down to crunch some crustaceans (crab, lobster, shrimp) or munch some mollusks (clams, oysters mussels, snails, squid, conch), consider the following:

• If you have family history of allergies (including hay fever or asthma), your chances of being allergic to shellfish increase.
• Most shellfish allergies are relatively mild and sometimes resemble food poisoning (which, as we all know, isn’t any fun).  
• Rarely, a shellfish allergy can trigger anaphylactic shock. Anaphylasis is a medical emergency that requires treatment with an epinephrine (adrenaline) injection (experienced travelers often carry an “epi” pen) and a trip to the emergency room.

If you have any symptoms after eating shellfish, even if mild, you should see a doctor — quick treatment helps avoid more or prolonged problems. It’s also important to consider the proximity of competent medical care. If you’re going to be far from reliable emergency services, don’t eat the escargot.  Yes, escargot, or land snails, are mollusks too and bear the same risks as their sea-dwelling brethren (not really brethren — all land snails are hermaphrodites, but that is a whole other story). 

If you decide that strong risk factors and poor medical options warrant avoiding shellfish, remember that you won’t be using menus replete with allergy warnings. Be aware of the potential for cross-contamination, and the sneaky places shellfish can pop up — like in condiments of East Asian food. Check out this listing of shellfish risks by world cuisines.

Some notes of caution: In some areas the favorite local dish can get you into some serious health problems, like the one recounted in a recent Wall Street Journal article.  In Santiago, Chile a bowl of mariscal contaminated with E coli had near tragic results for a young college student.  Also, be aware that mollusks harvested from waters polluted by sewage often carry the Hepatitis A virus, which they ingest when they feed. No amount of washing can remove the contagion.  So eat raw clams and oysters at your own risk. Even high-end restaurants in cities like Venice have served up “Hep A on the half shell.” We’ll cover hepatitis, its various strains and the immunization that is available in an upcoming post.